Unlocking Behaviors: Substance Use

By Ley Linder, MA, M. Ed, BCBA and Craig Escudé, MD, FAAFP, FAADM

This article is part of a co-authored series on behavioral presentations in which a physician and a behavior analyst provide insight into real-life case studies to share their expertise on how behavioral issues can be addressed in an interdisciplinary fashion. Dr. Escudé and Ley are recipients of the 2024 AADMD Excellence in IDD Journalism Award for this ongoing series. 

Daniel is a 33-year-old man with a diagnosis of mild intellectual disability. He does not have any chronic medical conditions but does take sertraline (Zoloft) for anxiety, which has been effective for him for the past two years. Daniel can independently complete most daily tasks, including personal hygiene, medication management, and laundry. He needs some support with budgeting, grocery shopping, and managing interpersonal conflicts. Daniel is friendly and very talkative, and he is especially proud of his job as a dishwasher at a local diner, where he has worked for over three years.

Daniel lives in a supported apartment with one roommate and receives periodic check-ins from support staff. He enjoys watching action movies, eating out, and hanging out with friends, some of whom he met through work and others in the community. Staff have noticed Daniel's appearance has changed over the past six months.  He has lost weight. His sleep schedule has become irregular. And he seems more anxious than usual. He started calling staff late at night, sounding confused or upset, and sometimes didn’t show up for work.

In early April 2025, Daniel was found sitting on the steps outside his apartment, visibly shaking and distressed. When a staff member asked if he was okay, Daniel said, “I think something’s wrong with me. I can’t stop thinking. My heart’s going crazy.” Staff contacted the nurse, who ruled out acute medical issues but encouraged Daniel to be seen by his primary care provider.

Medical Discussion

Daniel’s symptoms—anxiety, weight loss, poor sleep, and episodes of physical agitation—can be associated with several medical or psychiatric conditions, including hyperthyroidism, medication side effects, generalized anxiety disorder, and substance use. We don’t often think about substance use in people with IDD, but it does indeed occur. Substance use can result in physical symptoms such as elevated heart rate, insomnia, and weight loss, as well as emotional changes including anxiety and paranoia, many of which Daniel is experiencing.

Understanding the full scope of Daniel’s health means taking a holistic approach that considers physical health, mental health, medication interactions, and the impact of substances. Screening for co-occurring disorders in people with IDD requires thoughtful assessment tools that account for communication style and cognitive processing. Importantly, healthcare providers must avoid assuming that people with IDD do not or cannot use substances. This misconception can lead to missed diagnoses and untreated issues.

“We don’t often think about substance use in people with IDD, but it does indeed occur. Substance use can result in physical symptoms such as elevated heart rate, insomnia, and weight loss, as well as emotional changes including anxiety and paranoia...”

Behavioral Discussion

When behavioral analysts examine the behaviors of any person, many approaches can be taken, such as looking at setting events or antecedents, satiation vs. deprivation, or the functions of behavior. Another essential dynamic that can be addressed is explored by the simple question, “What has changed?” Daniel has been noted to have long-term global stability, more specifically characterized by well-managed psychiatric health for two years, competitive employment for three years, and activity of daily living independence. What has changed over the last six months?

At times, behavior analysts play the role of detectives trying to find the missing pieces that help explain the changes that are being observed. If a person has exhibited long-term stability (for Daniel, greater than two years) and suddenly exhibits a period of change with sleep, eating, and daily routines, in addition to mood and behavioral changes, we always “think medical first” (especially in this series). However, Daniel’s situation is an example of how we must be open-minded and look beyond the medical tests, particularly if/when they come back as not having any known concerns. 

The following are a few questions a behavior analyst may ask to explore Daniel’s recent changes: Has Daniel had any changes in his personal life that have caused stress, such as a recent death in the family or a breakup with a partner? What were the characteristics of Daniel’s psychobehavioral instability before the current and successful use of sertraline? Have there been any changes to Daniel’s job? A new manager, new job tasks, new peers? Work sites, particularly in the community, can be locations where some individuals have the least amount of support and are most vulnerable to negative influence. 

Outcome

Daniel hesitantly shared he had been using cocaine “sometimes” when out with friends because it made him feel more energetic and “cool.” He explained that he didn’t think it was a big deal at first, but now he was having difficulty stopping. Following his disclosure, Daniel’s team convened a person-centered planning meeting to explore how best to support him. They included a substance use counselor familiar with working with people with cognitive differences and adapted the usual treatment approaches to meet Daniel’s learning style. Visual supports, simplified explanations about the risk of cocaine use, and role-playing were used to help him understand triggers, cravings, and coping strategies.

Daniel agreed to start seeing the counselor weekly and identified a staff person he trusted to check in with regularly. The team helped him plan new social activities that didn’t center around the friends who were using substances. His job coach worked with his employer to offer flexible scheduling during his early recovery phase, and Daniel’s anxiety began to improve.

Perhaps most importantly, Daniel felt heard and supported, not judged. He said, “I didn’t think I could tell anybody. I thought I’d get kicked out of my apartment or lose my job. But you all helped me.”

Ley Linder is a Board-Certified Behavior Analyst with an academic and professional background in gerontology and applied behavior analysis. Ley’s specialties include behavioral gerontology and the behavioral presentations of neurocognitive disorders, in addition to working with high-management behavioral needs for dually diagnosed persons with intellectual disabilities and mental illness. He works closely with national organizations such as the National Down Syndrome Society and the National Task Group on Intellectual Disabilities and Dementia Practices. He is the Founder/CEO of Crescent Behavioral Health Services based in Columbia, SC. 

Dr. Craig Escudé is a board-certified Fellow of the American Academy of Family Physicians and the American Academy of Developmental Medicine and President of IntellectAbility. He has more than 20 years of clinical experience providing medical care for people with IDD and complex medical and mental health conditions. He is the author of “Clinical Pearls in IDD Healthcare” and developer of the “Curriculum in IDD Healthcare,” an eLearning course used to train clinicians on the fundamentals of healthcare for people with IDD.